package com.imau.filter;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@WebFilter("/*")
public class LoginFilter implements Filter {


    //1.定义拦截请求的白名单
    private static  final String[] whiteList = {"/login.html","/css/","/js/","/imgs/","/login",

            "/register.html","/register","/checkCode","/userCheckNameServlet"};
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }


    /**
     * 判断是否在白名单中
     * @param path
     * @return
     */
     public boolean isWhite(String path)
     {
         ///servlet-loginCase2/login.html
         for(String s : whiteList)
         {
             if(path.contains(s))
             {
                 return  true;
             }
         }

         return  false;
     }
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        //1.对象转换
        HttpServletRequest request =(HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse)servletResponse;

        //设置编码
        request.setCharacterEncoding("utf-8");
        response.setContentType("text/html;charset=utf-8");

        //获取请求路径
        String requestURI = request.getRequestURI();
        //判断是否白名单的路径
        if(isWhite(requestURI))
        {
            //在白名单放行
            filterChain.doFilter(servletRequest,servletResponse);
        }else {

            //不在白名单，判断session中是否有用户信息
            Object user = request.getSession().getAttribute("user");
            if(user!=null)
            {
                filterChain.doFilter(servletRequest,servletResponse);
            }else {

                response.sendRedirect(request.getContextPath()+"/login.html");
                filterChain.doFilter(servletRequest,servletResponse);
            }

        }




    }

    @Override
    public void destroy() {

    }
}
